Introduction: Kidney transplantation (KTx) is the gold standard for end-stage renal disease. Despite surgical and immunosuppressive advances, KTx success is hindered by rejection, mainly driven by donor-specific antibodies (DSAs). Immunoadsorption (IAS) has emerged as a promising therapy, selectively removing DSAs, unlike conventional plasmapheresis which eliminates all antibodies indiscriminately. Herein, we investigated the role of perioperative IAS and its link to the long-term outcome.
Method: In this retrospective single-centre cohort study, 50 immunized patients receiving perioperative IAS were compared to a group of 32 immunized recipients without IAS. Three and five recipients underwent combined kidney and pancreas transplantation, respectively. Patients were selected from our institution's transplant database. Demographic and clinical characteristics, including age, sex, underlying renal disease, human leukocyte antigen (HLA) mismatch and panel-reactive antibody (PRA) levels were extracted from medical records. Additionally, data on immunosuppressive regimens, including maintenance immunosuppression and adjunctive therapies such as plasmapheresis, were recorded. The primary outcome measures included the incidence of rejection episodes, both acute and chronic, and allograft survival rates. Secondary endpoints comprised serum creatinine levels and glomerular filtration rate (GFR).
Results: Baseline demographic characteristics, including sex, age and HLA-mismatch were similar between the two groups (p = >0.9999, p = 0.8418, p = 0.9508, respectively). In the IAS group, a significantly higher proportion of organ donors with ECD-status were represented compared to the control group (46% vs. 21.87%, p = 0.0350). Recipients in the IAS-group showed significantly higher levels of PRAs before KTx (mean: 19.20% vs. 13.56%, p = 0.0288), rendering this group more highly immunized at transplantation. GFR and creatinine levels at 7 days (p = 0.1647 and p = 0.2357, respectively) and 1 year (p = 0.3092, p = 0.4178, respectively) post KTx did not differ between the two groups. However, patients in the IAS-group showed significantly higher 1-year graft survival rates (98% vs. 81,25%, p = 0.0128). Episodes of rejection within in the first postoperative year did not differ between the two groups (p = >0.999).
Conclusion: In conclusion, perioperative IAS appears to offer promising outcomes after KTx, particularly in highly sensitized patients. Despite representing the more highly immunized cohort with a higher rate of ECD-donors, recipients in the IAS-group exhibited significantly higher 1-year graft survival rates compared to the control group. The utilization of IAS may thus represent a valuable adjunctive therapy in the management of immunized patients undergoing KTx, potentially improving long-term graft outcomes. Further prospective studies are required to validate these findings and elucidate the precise mechanisms underlying the observed benefits of IAS.